The present disclosure relates to a method of analysing tissue samples. The disclosure also relates to an instrument for analysing tissue samples and a computer readable medium for causing the instrument to perform analysis of tissue samples.
Some aspects of the present disclosure may improve intra-operative inspection of resection margins on a tumour resection specimen, to assess if adequate margins have been achieved. For example, oral cavity cancer is a major public health issue. Most oral cancers arise from the epithelium of the mucosal surfaces and are referred to as oral cavity squamous cell carcinoma (OCSCC). Mortality from OCSCC is high. Despite advances in treatment modalities (surgery, radiotherapy, chemotherapy), mortality has not shown significant improvement over the last decades.
Surgery is the mainstay of treatment for OCSCC. Complete cure may be accomplished by adequate surgery. Adequate tumour resection with acceptable remaining function and appearance is the main goal. For example, resection margins (defined as the smallest distance between tumour and resection surface) can be histopathologically classified as clear: >5 mm, close: 1 to 5 mm, and positive: <1 mm. Clear margins are regarded as adequate, close and positive margins as inadequate. In OCSCC, as in many other tumours, adequate tumour resection is often hard to achieve. The common causes are lack of reliable guidance of the surgeon and proximity of relevant structures in the operating field.
Patients with inadequate resection margins receive postoperative adjuvant treatment (chemotherapy and/or radiation), or re-operation. However, such treatments can significantly add to the morbidity of surgery while their efficacy is questioned. For the oral cavity, with its complex anatomy, visual inspection and palpation by the surgeon, are insufficient to warrant adequate resections. More information is needed to guide the surgeon.
Intraoperative assessment of resection margins on the resected tissue (referred to as “specimen driven”) is considered to be superior to assessment from the wound bed (referred to as “defect driven”), leading to a higher surgical success rate, lower local tumour recurrence, and increased patient survival. Guidance of surgery by intraoperative “specimen driven” assessment of resection margins is recommended. The procedure may greatly benefit from intra-operative histological assessment of resection margins for example by means of the so-called frozen section procedure. In the frozen section procedure the surgeon takes tissue samples from the surgical wound bed for microscopic evaluation by a pathologist. However, the procedure is laborious and time consuming and therefore limited to inspection of only a small number samples and fraught with sampling error. Inadequate margins are easily missed in the frozen section procedure, especially when the surgical wound is sampled.
There is a desire to provide methods and instruments which may improve accuracy of tissue sample analysis, in particular to better distinguish tumour and healthy tissue.